Compensation for variations exerted by a fluid within a container against the container has been a problem addressed by numerous approaches to its solution in the prior art. Early approaches have provided pressure relief value mechanisms associated with the container which would open in response to pressure in excess of a predetermined pressure and exhaust the fluid from within the container. Environmental considerations have dictated that such pressure relief valves vent to a second container in order to avoid pollution of ambient spaces.
A special case of a fluid exerting increased pressure upon a container is the case of water, which expands when frozen. Several examples of solutions to that dilemma have included U.S. Pat. No. 596,062 to Firey, which provides a hollow rubber core located at the center of a water pipe; U.S. Pat. No. 2,409,304 to Morrison, which provides a compressible core centered inside a water pipe; and U.S. Pat. No. 4,321,908 to Reed, which provides a central compressible core within a water pipe. Prior art approaches to the problem of expanding water (ice) within an enclosure show that much inventive effort has been expended in providing that the compressible core be centrally situated within a pipe.
There is a need for a simple apparatus for compensating for variations in pressure exerted by a fluid within a container against the container which is inexpensive to manufacture, simple to employ within the container, and precludes pollution of ambient atmospheric areas about the container without expensive additional compensating containers, or the like.